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A1.1 Multi-tenant service providers protect and separate all customer environments and data.

This requirement focuses on ensuring that multi-tenant service providers implement proper logical separation between customer environments. It ensures that providers protect customer data by preventing unauthorized access between environments and implementing controls to maintain separation.

Sub-requirements

A1.1. Multi-Tenant Environment Isolation Controls

Ensure secure isolation of customer environments in shared infrastructure to prevent unauthorized access between tenants.

https://WithPCI.com
4
Sub-requirements
5
Test Points
Moderate (2.5)
Implementation Difficulty

Control Types

Documentation
Governance
Technical
Process
Documentation: 1
Governance: 1
Technical: 2
Process: 1

Key Risks

Cross-tenant data leakage
Inadequate resource segmentation
Shared vulnerability exposure
Misconfigured access controls

Frequently Asked Questions

What defines a multi-tenant service provider under Appendix A1?

Entities offering shared services where customers share system resources (servers, apps, databases). Excludes co-location providers renting only physical space/bandwidth.

What documentation demonstrates environment isolation?

Required: 1) Network segmentation diagrams, 2) Hypervisor configuration reports, 3) Tenant access control matrices, 4) Penetration test results validating isolation.

How are responsibilities divided between provider and customer?

Formal agreements must define: 1) Shared vs dedicated controls, 2) Compliance validation scope, 3) Incident response duties. Reference PCI DSS Requirements 12.8-12.9.

What virtualization safeguards are required?

Implement: 1) Hypervisor hardening to CIS benchmarks, 2) VM escape protection mechanisms, 3) Storage encryption per tenant, 4) Network microsegmentation.

How often must isolation controls be validated?

**Quarterly** automated scans + **annual** penetration tests. Cloud environments require continuous configuration monitoring.

Common QSA Questions

Show evidence of cross-tenant penetration testing

2025-Q1 report used Metasploit to simulate VM escapes across 450 hosts. Results: 0 successful breaches. Remediated 3 high-risk hypervisor configs.

Demonstrate cryptographic tenant data segregation

We use AWS KMS customer-managed keys with IAM boundary policies. Evidence includes CloudTrail logs showing zero cross-tenant key access.

Provide shared responsibility agreements for SaaS customers

Contracts specify: 1) Provider manages VPC/VLAN segregation, 2) Customers handle app-layer controls, 3) Joint patching SLAs. Validated through CSA STAR reports.

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